Typewriting machine



Dec. 26, 1939. w A, D BSON 2,184,736

W. A. DOBSON TYPEWRITING Dec. 26, 1939.

MACHINE Filed Aug. 4, 1937 3 Sheens-Sheet 2 INVENTORI MM% Dec. 26, 1939. w A DOBSON TYPEWRITING MACHINE Filed Aug. 4, 1937 3 Sheets-Sheet 5 Patented Dec. 26, 1939 PATENT OFFICE mnwnrmw mdnmn William A. Dobsoll, Wethersfleld. Oonn. asslgn0r to Underwood Elliott Fieber Company New York, N. Y. a cor'poration 01 Delaware Application August 4. 1937, Serial N0. 157,236

17 Olaims. (C1. 19722) This invention relates to light-duty typewriters in the dass cf standard portable machines, and relates more particularly to the typeactions and to case-shifting mechanism thereof, the latter being efiective in shifting the type-bar system or basket.

A general object o'f the invention is to preserve the features of compactness, so essential in this dass of light-duty portable machi'nes, especially with reference to the height of the t5'1pewriter. In accordance with the invention the system of type-actions, including key-levers and interconnecting mechanisni, aflords a olose nesting of the parts in a relatively shallow machine, although.

the parts assume adequate proportions and ample lengths to afiord a smooth dependable action during typing and assure free, unencumbered movement of the basket in case-shifting.

A further aim of the invention is to aflford an easy finger-touch on the keys, and celerity of operation with minimum inclination or tilting of the keys during the key-strokes. These features have been obtained heretofore, mainly in standard typewriters, by employing key-levers of greai; length extending back under the type-bar system and pivoted at their rear ends. Key- -levers of this sort are embodied in the present invention, but in a light-duty portable machine, without adding to the height. of the machine but rather minimizing its height.

Another aim of the invention is to afford operation of the type-bars by the described underlying system of lang key-levers, by means of inuermediate connections which will permit the up-and-down shifting of the type-bar system while the keys remain stationary and which will enable the described key-levers to operate said type-bars by means of' sub-levers of maximum length thereby 150 secure ease of action While permitting exceptional compactness of the machine, especially as to height, by mounting said sub-levers forwardly of the type-bar system and reaching up in front of the type-bars and counected to the rear ends of the latter by means of links which are directed downwai*dly from the sub-lever connection to a point below the adjacent type-heads anti then extend rearwardly to connect to the short drive arms of the typew ends below the key-levers to extend up between the key-levers, terminating at the upper ends above the level of the types, while the links dip lever5' aiidfare so shaped um at the beginning downwardly Irm their artlculations to the sublevers and then run back to the type-bars. These upstanding sub-le'vers with thelr cam-arms, find ample room in front of the type system ab the rear 01 the key-board and there is ample clear- 5, ance of the key trains one from another.

The type-bar segment extends downwardly and forwardly trom the platen a1: such angle that types strike at a point a little above the level of the platzen axls. The type-bars, als rest, are disposed in a substantially horizontal front and back plane, the am o1 the type-bar rest engaging the type-heads, being of lesser curvature than the type-bar-pivot arc': so that the typebars particularly at the sides of the system, diverge slightly from each other to afl ord more clearance for the types. The sub-levers are pivoted on a. common transverse horizontal fulcrum-rod and are made in gradual lengths so that their terminal ends collectively define an 20 arc, conforming, approximately, with the arc assumed by the type-heads at rest.

The arrangement of the sub-levers in which their free ends are disposed to project in freut of the type-bar basket and including type-:bar 25 links directed downwardly and rearwardly to collectively define a recess or trough, permits the use of shorter type-bars, thereby minimizing the height of the machine. Such arrangement allows the type-bars come to rest in a. position nearly horizontal and, in view of the backward tilting of the type-bar segment, the type'-bars are caused to diverge or spread fromeach other and, therefore, the type-heads thereon may be closer to the fulcrum point to minimize the length of the-type-bar.

The types lie in the type ba.sket which is normally disposed above the curved row cf type-bar links a.ncl, in case-shifting to the upper type' characters, that is. in lowering the type basket, the arrangement permitsthe forward ends of the typebars to drop back of the upper ends of the sub-levers and into the recess' aiforded by the L-shaped form of the type-bar links.

In combining seid. key-levers with said sublevers, type-bars and links, the links are formed with cam-shaped slots in which plus or wrists on the sides of the key-levers' operate. The slots curve downwardly and rearwardly from said. pins or wrists, the slots in diflerent sub-levers having 50 difierent eurvatures to compensate for varying effective lengths am]. strokes of the corresponding type -ac'ztion parts. These slots are formed in members; which extencl forwardly from the subcf the stroke there ls considerable motlon of the key employed in eflectlng a short motlan of the sub-l'ever und type-bar so that the start 01 the type-bar in motlon 1s easy end I;hus an ehsy operatlon is obtalned. The lower part 012 the slot however, curves backwardly ar becomes more abrupt so that at the last part; o1 the key stroke. the type-bar Is speedecl up and at the same time the momentum 01 the aperator's hand Is gradually absorbed by the type-bar; Tims, the type is cu.shloned both at the begl'nnlng 01 the strake und at the concluslon 013 the stroke.

Other teatures and advantages will hereinafter appear.

In the accalnpanylng drawlngs Figure 1 a perspectlve vlew 01 the typewri ing machine ex'nbodylnz the lnventlon showing the type basket in lowered posltion tor upper case typlng the casing and certaln portions. of the type-actlon system being o1 n1tted lfor clarlty. Flgure 2 is a fragmentary Sectional view haken an a. freut and back plane at the center 01 the machlne end lllustratlng typ ical center und auter type-actions 015 the system, lncludlng the caseshlft mechanlsm, the type-bar basket being shown in raised posltlon for lower-case typlng.

Flgure 3 ls a fragmentary transverse sectl0nal view Ighrough the typewrlter, taken an the plane just torward af the type-bar segment, I;o illustrs;te the mean.s tor mounting end gulding the sesment for case-shltt movement end the caseshiitlng stops thereof, and

Flgure 4 is a view simllar to Flgure 2 but showing a center type-actlon only, the -type-bar basket belng lowered rar upper-case typing. In the preferred embadlment o! the lnventlon xllustrated, a typewriting machlne o1 the standard portable dass is shawn, lncludlng a Immework of vertlcal side plates 5, a traut platze I, and suitable cross-members such as' the transverse bar 8. A system o1 key-levers 0 is pro vided, each extending substantially the depth o1 the machine, being plvoted an a transverse fulcrum-rod I0 at their rear ends end yleldably held m normal position by springs II, against a stop I2, the key-levers extending through gulde-slots in the frant plate I and carrying keys I3 at their forward ends, the keys being arranged in a series of transverse banks er rows Iorming a keYboard.

Each key-lever 9 has. extendlng laterally therefrom adjacent the forward end, a wrlst or. pin II engaging in an arcuate slat I5 cut in a forwardly extending me1 nber I5of a sub-lever I I. A series of sub-levers I'I ls pravided, each one af the series belng disposed in upstandlng position am! Iulcrumed an a rod I 0 mounted in the transverse bar 5. thelatter lncluding a serles' o1 gulde-slots I5 I:o gulde the res'pectlve sublevers I'I in a vertlcal plane 01 travel. T0 aflord adequate lengt h tar the varlaus sub-levers I'I, particularly those at the center af the machlne, the fulcmm I0 of the sub-levers ls disposed substantlally at or close to the bottomof the ma- China to extend upwardly therel'rorn between the key-levers 0 in crosslng relatlon therewlth.

The cam-slots I5 are dlrecttad downwardly und rearwardly in the sub-levers I'I so that, darin: depression o1 a key-lever l-,. the pln I4. aclzlng 8ainst. the lower edge 01 the slot II, cams the sub-lever I1 to swing forwardly o! the machlne an lts plvot I8. T0 compensate i'or certaln dlflerences in the carrespondlng"patts 02 the various type-actlons. such, tor example. es the varlous lengths a! key-levers and the llllcrent lefltr slots I5 for the respectlve type-actlons vary in angle of lncllnatlan and degree of curvature. 'I'hat 1s to-say, the cam-slats I5 tor the outslde type-actlons. see Flgure 2, are lnc llned less than slots o! the central actions since the outer subleverbelng langer. requlres a lesser throw I:a actuate lts type-bar. Further, the degree ot curvature for each cam-slot I5 ls such that at the beglnnlng of the key-stroke there ls a sreater leverase to start the type-bar in motlon and the cam-slot I5 gradually flattens out to decrease in angularity so that toward the end o1 the key-stroke, the leverage is so decreased as to absorb the momentum'of the operators band vs the type approaches and strikes the platen.

These dlfierences inthe slots I5 have the eflect of coordlnating th'e respectlve type-actions with each other to assure a substantially uniform depth o! key-strake and provlde adequate leverage throughout the type-action system. As ls well known, a certain type -actlan may be guided by depression of a key I3 in the rearmost bank, und the adjacent type-actlon may be operated by a key in the flrst bank, the mentianecl keys diflerlng someWhat in the efl'ective throw o! the p1n I4 an the cam-slot I5. Slmilarly, as will be apparent in Figure 2; the center type-actions h8.Ve a, relatlvely short sub-lever I'I as compared wlth the -sub-lever for the outslde type-actlon shown, the latter being comparatively lang. Although the free end o! each sub-lever I'I travels an approximately uniform distance durlnz operatlon, the angular throw o1! each dlfl.'ers whlch dlfl'erence ls accommodated by the mentloned varlatiam in the respective cam-slots I5.

A segment plate is provlded Ior mountlng and guldlng a system of type-bars 2I in swinglng to and from the platzen 22 in typing. The type-bars 2I are pivated an the segment plate 20 by an arcuate pivot rod 22 thereon; the typebars belng disposed at the1r pivoted portlons in a serles o'f radial slots cut in the segment 20. The segment 20 has a supportlng frame 25 extendlng laterally trom each slde thereof by which same ls mounted ior case-shltt movement, to be later particularl2ed.

Arms 20 extend Iran: the frame 25 in support 01 a curved rest 21 lncludlng an arcuate channel bar end a cushion 20 inserted therein against which the type-heads o1 the type-bars 2I rast in inactive position. The pa'rtlcular arrangement o1 the type-bar basket, lncludlng the segment 20, the type-bars 2I, and the rest 2'I, presents a condition eflectlve in somewhat reducing the height o! the machlne. The curvature o! the plvot rod 23 is of a sultable radlus or curvature to guidethe type-heads into the strlklng position an the platzen 22 and the curvature o1 the rast 2'l ls somewhat flatter or o1! greater radlus than that of the pivot rod 25, so that the resbective type-bars 2I, partlcularly those aI: the sldes o1. the machine. are flared out as in fan formatiom to dlverge irom each other thereby afl'ording greater spaclng between the respectlve typeheads' thereof. Since each type-head requlres a certaln clearance, thedlvergence 01 the typebars 2I permlts a shorter type-bar, hence reduc- Ing the owierall helght o1 the machine. The relatively'flat curval;ure 01 the rest'.2'l es campared wlth the curvatu re o! the pivot rod 23, causes the tyjae-bars 2I a1; the sldes bf the machine to'ssume a lower posltion at rast. The segment P.1flte 20 is tllted at an angle trom the vertlcal, Flsme2soastoraisethetypelineonthe the type-bars 2l in an angle greater than the usual ninety degree am.

Each type-bar 2I includes (drive-arm 23 ex-' tending rearwardly ahd downwardly thexefrom. Bach drive-arm 23 is operably connected to a corresponding sub-lever I'I by a Iink 30 flexibly joined at 3l to the sub-lever ll and at 32==t0 the drive-arm 23.

As aforeindicated, the. series 015 sub-levers l'l are oi various lengths so thai: their free ends, artic1flated to the links 30, deflne an ar c formation, see.iilgure 1, in circumiacent relation to the type-bar ends in rest position, the sub-lever ends being disposed in iront of the type-heads. T0 accommodate the type-bar basket'in either upper or lower case-shifl: position, theseries cf links 30 a're bowed downwardly so as to deflne a. trough in recess into which -i:he type basket '32 at the drive-arm 29.

is nested, each link, 30 being preferably directed downwardly from the polnt 3l at the sub'-lever IT am! -bent to extend rearw8rdlyjo the point The arrangement of the type actions as sei: iorth aflords certain econoufies in manufacture, particularly in that same A 30, and the type-bars 2l includlng the drivearms 23 facilita'tes case -shift x'novemeni; of the type-bar basket without. afiecting the type ac- .tion, this advantage being had particularly because of the extension of the sub-lever ll in front of the type-bars 2l. The segment 20, in

case-shift movement, travels down and up in a plane substantially Parallel to its normal face and reciprocates a maxlmum dlstance, approximately one-quarter inch. In. relation to. the pa'rts of the mechanlsm, as shown in Figure 2, tl1e' type-bar basket is in upper position from which it will be noted that the pivot point. 32, duxing case-shift movement to lower position, lowers approximately one-quarter inch. The pivot poini; 3I is therefore disposed in a 'plane perpendicular to the plane of travel of segment and intersecting the poini. 32 midwaybetween th e two extreme posltions thereof. In oth r words. the point 32 travels during.case shifting one-eighth inch either side of a plane normal to the segment 20 andintersecting the point 31 and in view of the adequate length of the link 30,

the poiht, 32 moves in a substantially flat am which dig resses only sllghtly from the path of travel oi the segment 20. whichdigression is allowed by the ixiherent looseness of points 3l, 32.

Although, in the present embodiment of the the pivol:

invention illustrated, th e tmie-bars 2I are shown in approxlmate horizontal position at rest, and the segment 20 ls tilted backward a1: an angle of usual 90 degrees stroke, for example; 100 degrees. As aforelndicated, such an increased stroke perx'nits the i1se oi shorter type-harai aiid. therefore, io'r a given elevationof the' platen- 22.

fihepivot cf the type-bars"may be' higher=thrin usual to aiiford amp1 clea;ance between the t'ynebars and llnksfoi downwixrd'caSe-shiit 'movment.""lhese featuns all result in broducirig a withstanding the compa'cisnes; '0f the machine.

shift movement, prefer'ably a.sshown in F'i3ur6s 1 and 3. The segment-supporting frame" -'has its respect ive endsbent 01 otherwise 'fofm1d'to provlde .oppositely-facing raceways 33, including dependlng portions-34, each racewayhavihg slots 35 formed therein to :omperate with a sin-' gle ball or 'roller 35. A complemental rapeway 31 for each ball 36 is mounted on the respctive side plates 6 of the main frame, the respectlve raceways 31 including slots 35. for guidingly retaining the ball 36 in case-shlft niovement.

The case shifting of the segment 20 is actua;ted-

-by the mechanism shown in Figure 2 which includes a'case-shift lever40 fulcrumed at 4l on the sideplate Sand defining a T-shaped formation having a cross member 42 flexibly joined at its upper e'nd to a link 43. The depending portions 34 of the segment frame 25 each have flexlbly connected thereto an arm 44 of a bellcrank 45, the latter being pivoted by means of a lateral rock-shaft 46 and in cluding an arm 41 flexibly joined to the other end of the link 43. A case-shift mechanism similar to that described is provided at each side cf the machine. the

operation of each mechanism being coordinated throngh the rock-shaf t 43 which is journaled in the respective side plates 5 and ha s flxedly mounted' thereon each of the bell-cranks 45.

T0 minlmize the efiort of the operator required in case shifting, an inltially tensioned sprin'g 48 is effective on each of the arms 44 so as to counterbalance the load of the type-bar basket efleci;ive on the case-shift mechanism.

- Means are provided for limiting case-shift movement, embodying case-shift stops illustrated in Figures 1 and 3., Each laterally extendlng portion of. the segmeni; frame 25 has formed thereon a stop lug 50, and a bracket 5l extends" from each side platze 5 being formed to present a fian'ge 52 in parallz'alism with thelug 50. The flange 52 of each case-shift stop carries a palr of stop screws 53 and 54 threadedly engaged therein, each screw including a lock-nut thereon. The screw 53 has-its free end deperlding from the flange52 1:0 abut the lug so as to determine the upper position of the segment 20.

The screw 54 also depends from the flange 52 and extends through an aperture in the lug 50 so as to serve in limlting the downward travel of the segment 20, the screw 54 including a head or collar 55 for engagement with the lug50 as the segment 20 reaches lower position. Adjustment ol the respective screws 53 or 54 determines -wlth accuracy the position of the type-bar basket, .particulalrly the upper and lower type case relative to the printing line n the platen 22.

In general, the correlation of the parts of the type-actlon as descrlbed, and the type-bar assez'nbly o'r basketas sei: forth. pro'duces a number of pertinent features advantageous in the eflicient operation of the machine; and als the -sa1ne time presents a compact organization of mechanism so desirab le in inachines of the portable li-ght-duty class. The tilting of the segment assures greater' visibility o1 the work and the horizontal arrangement oi. the type-bars atiords a machine o! lesser height and facilitates the nesting of the type basket Within the trough Iormed by the recessed or downwardly bent links.

l"urther. gradual lengths of the sub-levers. de-

flning an arc in conformation with the typeheads at r'est, permits allocating the points of articulation thereof to the type-bar links in such position with rei'erence to the plane of travel of the segment as to obviate any efiect on the type-actions during case-shiit movement of the segment, at the same time ailording an arrangement which permits the use of, substantially uniform links throughout the type-action system.

Variations may be resorted to within the soope of the invention, and portions of the. improvements may be used without others.

Having thus described my invention, I claim:

1. In a. typewriting ma'chine having a itamework and a platzen carried thereon, in combination, a series of type-bars including drive-an'ns deflning a type-bar basket mounted for caseshift movement relative to said platzen, means for shifting the type-bar basket in a case-shiit movement, a system of key-levers, a series of subleversfulcrumed at their lower ends and extending upwardly therefrom across the System of key-levers and in front of the type-bar basket, means operably connecting said key-levers to said sub-levers. and. a series of links operably connecting said sub-levers to said type-bar arms and bowed downwardly to form a'trough for disposition of said type-bar basket therein.

2. In a typewriting machine having a frame work and a platzen carried thereon, in combination, a series of type-bars including drive-arms, resting normally in a substan'tially horizontal plane and defining a type-bar basket mounted for case-shift movement relative to said platen, means for shifting the type-har basket in a caseshift movement, a system cf key-levers fulcrumed at their rear ends, a series of upstanding sublevers fulcrumed at their lower ends and extending upwardly therefrom across the system 015 keylevers and in front of the type-bar basket, means operably connecting said key-levers to said sublevers, and a series of links operably connecting said sub-levers to said type-bar arms and bowed downwardly to form a trough for disposition of said type-bar basket thereim 3. A typewriting machine, as sei: fo'rth in claim 2, in which the sub-levers are of various lengths increasing from the center of the machine and have their free ends deflning an outline in couformation with the associat.ed type-bar drivearm outline to permit uniformity of the counecting links.

4. A typewriting machine, as set forth in claim 2, in which the link formation defines a trough into which said type-bar basket may recede for upper case-shift movement.

5. A typewriting machine, as set forth in claim 2, wherein the point of connection o! said suble vers to said links is in front of and adjacent the type-heads of said type-bars.

6. A typewriting machine, as set forth in clalm l, in which said links are articulated to the fr.ee ends of the sub-levers and the points of articulation collectively define a line circumjacent the type-bar free ends.

7. In a typewriting machine having a framework and a platen carried thereon, in combination, a series o! type-bars including drive-arms, resting normally in a substantially horizontal plane and deflning a. type-bar basket mounted !or case-shift movemeni: relative to said platzen. means tor shifting the type-bar basket in a esseshift movement, a system oi key-levers oi the second order tulcrumed at their rear ends adjacent the back 01 the machine. a. series o1 upstanding sub-levers o! the second order tullcrumed for dis'position of said type-bar basket therein.

stantially common center, each o! said type-bars normally resting in a -substantially horizontal 'plane, said segment being tilted downwardly and forwarclly from said platzen so that the respective type-bars diverge relative to each other at rest from the pivot s thereof, a sy'stem of key-levers extending beneath said type-bars and pivoted ab their rear ends, a series of.upstanding sub-levers fulcrumed below said key-levers and projecting' upwardly through the system of key-levers to terminate in front' of and proximal to the free 1 ends of said type-bars, links operably connecting said sub-levem to said type-bars and bowed downwardly to form a trough for admission 01 said type-bars therein, and means for actuating said sub-levers by movement oif said key-levers.

9. A typewriting machine, as sei: forth in claim 8, in which the sub-lever free ends collectively deflne a line circuinjacent the type-bar free ends.

10. A typewriting maohine, as set forth in claim 8, including a type-bar rast engaging the typeheads of said type-bars in inactive position, said links dipping below said rest and extending rear wardly to the articulation with said type-bars.

- 11. A typewriting machine as sei; forth in claim 8, in which the key-levers are of the second order and fulcrumed adjaceni; the back of the machine. and the sub-lev.ers are of the second order and fulcrumed at the bottom of the machine.

12. A typewriting machine as sei; forth in claim 8, in which the key-levers are of the second order and fulcrumed adjacent the back of the machine. and the sub-levers are of the second order and fulcrumed at the bottom of the machine, the keylevers and sub-levers crossing each other intermediate their ends.

13. A typewriting machine as set forth in claim 8, in which the key-levers are of the second order and fulcrumed adjacent the back of the machine, and the sub-levers are of the second order and fulcrumed als the bottom 015 the machine, the keylev.ers and sub-levers crossing each other intermediate thelr ends, said sub-lever actuating means being effective at the region of intersection of each sub-lever and key-lever.

14. In a typewriting machine having a framework and a. platzen carried thereon, in combination, a series cf type-bars resting normally in a substantially horizontal plane and defining a type-bar basket mount.ed for case-shift movement relative to said platen and presenting an arcuate formation of the type-heads in a substantially vertical plane, meains for shifting the type-bar basket in case-shift movement, a system of key- 2,1s4,7se

levers fulcrumed a1: their rear ends, a series 01 upstanding sub-levers of gradual lengths increasing from the center of the machine and fulcrumed at their lower ends, extending upwardly therefrom across the system of key-levers and terminating in front of the type-heads, the terminals of said sub-levers collectively defining an am circumjacent said" type-head formation, a. series of links connecting said sub-levers to said typebars and bowed downwardly to form a trough for admission cf said type-bars collectivsely therein, an arcuate s1ot in each of said sub-levers, and a pin on each of said key-1evers engaging said slot, whereby said sub-lever is swung forwardly to actuate said type-ba: during depression 01 said keylever.

15. A typewriting machine as sei: forth in claim 14, in which the arcuate slots in the respective sub-levers inc1ine ab decreasing angles beginning f rom the center of the machine, to compensate for the increasing lengths of the sub-levers.

16. Ina typewriting machine having a. framework and a platzen carried thereon, in combination, a series 013 type-bars including drive-arms, resting normally in a. substantiaily horizontal plane and defining a type-bar basket, a. system of key-levers fulcrumed at their rear ends. a. series of upstanding sub-levets fulcrumed at their lower ends and extendin upwardly therefrom across the system 01 key-levers and terminating in front y 01 the heads of the type-bars, the fulcrums 01 said sub-levers being on a transverse line forward of the type-bar heads, a series of links articulated to the terminais of said sub-levers and to said type-bar arms, said sub-levers having s1ots extending upwardly and forwardly of the sub-levers, and pins on said key-levers cooperating with the slots to drive the type-bdrs, said pins at rast being substantially forward of the terminals of said sub-levers.

17. In a, typewriting machine, in combination, a series of type-bars resting normally in a substantially horizontal plane and defining a typebar basket presenting an arcuate array of the type-heads in a substantially vertical plane, a system of key-levers fulcrumed at their rear ends, a series of upstanding sub-levers of 'gradual lengths increasing from the center of the machine, fulcrumed at their 1ower ends and extending upwardly therefrom across the system of keylevers and terminating in fronb 01 the typ.e-heads the terminals of said sublevers collectively deflning an arc circumjacent said type-head array, and a series of links Connecting said sublevers to said type-bars and bowed downwardly to form a trough to admit the type bars therein.

WILLIAM A. DOBSON. 

